Device for measuring the thickness and/or the unevenness of slivers

Abstract

A sliver measuring device includes a pair of rollers (6, 7) which limit two sides of a rectangular measuring space (3). A third side of the measuring space (3) is closed off by a guide roller (8) or by a guide plate. A measuring element (5) for the thickness or non-uniformity of the sliver is arranged on a fourth side of the measuring space. The rollers (6, 7) serve to compact the sliver in the measuring space. The measuring element (5) is formed by a leaf spring provided with strain gauges. Since the sliver is actively driven at the measuring point, this leads to an increase in the compaction of the sliver and thus to an increase in the measuring accuracy dependent upon the compaction. On the other hand, the inertia of the measuring element is very low.

What is claimed is: 
     
       1. Device for measuring the thickness and/or the unevenness of slivers, in particular on preparatory spinning machines, having a compaction element compacting the sliver and a measuring element for the thickness or non-uniformity of the sliver, which measuring element mechanically scans the compacted sliver and is formed by a leaf spring provided with strain gauges, wherein the compaction element is formed by a pair of rollers (6, 7) which limit two sides of a rectangular measuring space (3) which is closed on three sides and on whose fourth side the measuring element (5) is arranged. 
     
     
       2. Device according to claim 1, wherein the third side of the measuring space (3) is closed off by a guide roller (8, 18). 
     
     
       3. Device according to claim 2, wherein the rollers (6, 7) are driven, and in that the guide roller (8) is arranged on the drive spindle of one of the rollers and directly next to this roller and has a shoulder covering the third side of the measuring space (3). 
     
     
       4. Device according to claim 2, wherein the rollers (6, 7) are driven, and in that the guide roller (18) is arranged perpendicularly to the rollers and is coupled to the latter as a drive and, with its periphery, engages between the rollers on the third side of the measuring space (3). 
     
     
       5. Device according to claim 1, wherein the third side of the measuring space (3) is closed off by a guide plate. 
     
     
       6. Device according to claim 1, wherein the leaf spring (10) is of elongated design and is fastened at one end (11) to a support (9). 
     
     
       7. Device according to claim 6, wherein the leaf spring (10) is oriented in the direction of the straight connecting line between the axes of the two rollers (6, 7). 
     
     
       8. Device according to claim 7, wherein the leaf spring (10), in its center part, is provided with a web (13) which carries a measuring lamina (14) provided for contacting the sliver (1). 
     
     
       9. Device according to claim 8, wherein at least one pair of strain gauges (D1-D4) is provided, of which one is arranged adjacent to the said web (13) and the other is arranged adjacent to said one end of the leaf spring (10). 
     
     
       10. Device according to claim 9, wherein the strain gauges (D1-D4) are arranged on a side of the leaf spring (10) remote from the web (13) having the measuring lamina (14). 
     
     
       11. Device according to claim 10, including a supply of compressed air; and wherein at the side of the leaf spring (10) carrying the strain gauges (D1-D14), an intermediate space (12) is formed between this leaf spring (10) and its support (9), supplying compressed air for cooling and/or cleaning purposes. 
     
     
       12. Apparatus for measuring the thickness and/or unevenness of slivers, comprising means defining a rectangular space through which a compacted sliver to be measured passes; said means including a pair of opposed rollers on opposite sides of said sliver and defining two sides of said rectangular space, a member having a surface defining a third side of said rectangular space, and a measuring element defining the fourth side of said rectangular space and being in position to be pressed against by the compacted sliver in said space with a force proportional to the thickness of such compacted sliver.